Concentrator



Feb. 3, 1942. w C, HUDSON 2,272,005

CONCENTRATOR Filed Oct. l, 1940 41".1 y y 7 48 mol/? 2.0 4? Hf PatentedFeb. 3, 1942 14 claims. lol'. y20e-'458)' e `rTheinventionrelatesrparticularly toa concentrator or separating device and isespecially ladapted for separating particles of material car- 1redby aliquid stream ork current. rIfhe device 4 is intended to operate on theheavier particles and separate ythem from the stream carrying thejlighter particles which may pass on to waste or further treatment.vThere are many industrial Iuses' for such a device. Specific andimportant usesv are in the-treatment of mined material. Thus astream ofWater carrying solids of diierent specic gravities may be treated by thepresent invention to concentrate or separate the heavier and generallymore valuable solids, including suchmaterials as flour gold fromsaprolite or sand, and metals from their gangue, etc.

It has been found that liquid carrying solids whenpassed at proper ratesof iiow through a curved channel tends to collector concentrate theheavier particlesat certain points in the path -f of travel. When` acurrent impinges against a concave Acurve there is a tendency for. thesolid particles carried to vrconcentrate close to the curved Wall. Whenthe current leaves the con-v cave point in the wall itspreads across thechannel .andtends to throw the heavier particles or concentrate more'orless directly toward the other side of the channel; their coursevarying .with the character of the liquid, the speed of flow and withthe weightof the specific particles be- -the main part at least of theheavier particles the ychannel may be'sinusoidalor made up of aplurality of succeedingv reverse curves. A few 4'curves in the channelmay be su'icient andthey may be all included in a relatively short runor quantity of material it may then be desirable to assemble a pluralityof the-relatively small channels which may thus .produce-separation orconcentration of a sufiicient amount ofY material to make the operationcommercially practicable.

In vorder to take advantage of the factthat a stream of liquid carryingsolids of different gravi- Vties and flowing aroundl a curveso as todeposit the `heaviest solids -in a restricted area ofthe stream bed itmay be desirable to decrease the velocity of the stream of liquidcarrying such ysolids of different specific gravities at appropriatepoints so as to'aid in such deposit'of the .heaviest solids. V'I'his maybe accomplished by glengthof channel. In order to handle a larger 49means of appropriately placed and positioned baIlles ory rilesassociated with whichmay be p rovided openings in `the bottom of theAchannel through which may be dropped and removed the .heavierparticles,"s eparation and saving. of whi'chmaybespeciallydesirable. 1For thebest procedure with a specific materia it maybe desirable to havea lcarefully designed structure inwhich the formand proportions arecarefully designed so as to most eiectively cooperate with the liquid atthe mosteffective speed but such aspecic, refined arrangement may not benecessary vfor carrying out the invention which mayproduce desirableresultsfin many forms and proportions.

n Infth accompanying drawing, for 'the purposeof illustrating theinvention but without limiting it, is shown one `speciiic Aform ofapparatus Awhich is 'especially' adapted to the separation ofsuch'materialas Ilour gold vfrom Vsaproliteor sand. yFigure 1 isa moreor less diagrammatic plan view of'a pair of concentrating channelsenclosed in an outer casing. Fig.`2 is a side elevation of theapparatus. Fig. 3 is kan enlarged'fragmentary planview showing. detailsof form. Fig. 4 lis an'enlarged fragmentary cross section on the line 44 offFig. 1. j i

As illustrated the ydevicev may consistof an outencasing vII'I whichmaybe a sheet of metal turned upat its lsides. to make side walls I I asshown infFig. 4;. For convenience the side walls II `may be straight orof any desirable form. .Mounted within the side Walls II are shownrthree longitudinal wall members, I2, I3; I4 forming between them two'channelsthrough'v which the liquid may: pass forconcentration. Thewalls I2, I 3,` I4 are each curved but are solderedor otherwise mountedon vthe bottom substantially parallel to each other so that the channelI5 between the walls I2 and I3 is lpreferably of substantially the samewidth throughout its length' and the channel I6 between the walls I3 andI4 is preferably of substantially the same width throughout its length.As illustratedeachchannel andits `wallsjare made up of a succession of'reversed curves. Thus the channel beginning at the left in Fig. 1 makesacurve toward the bottom at I1 immediately followed by a rcurve towardthetop at I8 and so onr throughout the length ofthe channel. Thereareillustrated 'four of these double 'curves' which maybe a suitable numberfor practical operation,' although any other number maybe chosen andemployed.

' It Will be seenfthus, Athat each wall of the channel consists of asuccession of convex and concave curves, there being opposite the convexcurve on each wall a corresponding concave curve on the opposite wall.The terms concave and convex are employed here with respect to themiddle of the channel. Thus the curve at l1 in the upper wallillustrated in Fig. 1 is a convex curve while the curve at IB in theupper wall is a concave curve. It will be understood that liquid inpassing from left to right for instance in Fig. 1 through the channelmade up of succeeding reverse curves will constantly have its directionchanged and when the direction is changed the tendency will be toconcentrate and position at least the heavier solid particles carried bythe liquid. In order to take advantage of this arrangement andpositioning. riles or baiiles I9 may be appropriately placed so as to bein the path of the portion of the liquid carrying the heavier particles.As heavier particles thus impinge upon the riflie or baiile their speedwill be stopped or reduced and they may be deposited on the bottom ofthe channel. Each baie I9 may be curved so as to present a convexsurface to the material ilowing over or against it. 'I'his arrangementtends to cause the heavier particles to deposit and also tends to notfill up or dam the channel but to allow the unseparated material to passonward. Preferably at the down stream portion on the convex side of thebaffles I9 there may be provided openings or holes 20 in the bottom ofthe channel through which the impeded or settled heavier portions of thesolid carried by the liquid may pass into a trough, pan or launder 2|which as is illustrated in Fig. 2 may be placed immediately under thetrough I0.

As illustrated in Fig. 2, in order to aid in the operation of the deviceand the passage of the liquid and the recovered material the trough Iand the trough 2l may both be mounted on bases so as to inclinedownwardly from the left hand end to the right hand end, that is, in thedirection of flow of the laden liquid. This will tend to aid the freeflow ofthe liquid bearing the solid through the trough lil and may aidin the collection and removal of the heavier particles from the trough2l. The angle at which the troughs are mounted is not essential to thepresent invention although in the specic apparatus to be described indetail it has been found that an angle or grade of about is suitable andmay be desired.

In one specific construction in which the trough is set at a 10 gradethere has been satisfactorily treated a liquid carrying to 20% solids ata speed of about 8 gallonsl per minute. Such a structure may be about 10feet long, in which arrangement the successive concave curves in thechannels may be about 30 inches apart. The width of each channel may beabout four inches and the height of the sider walls may be about twoinches. The concave and the convex curvature of the side Walls may besymmetrical and both may be formed with a radius of about 15%E inches,it being noticed that this radius is nearly four times the width of thechannel. With this arrangement all the succeeding curves on oppositesides of the channel such as those marked A B and C in Fig. 3 may have acommon tangent. Thus the same line which would be tangent to the lcurveat C would also be tangent to the curve at B and the curve at A etc. Bysuch an arrangement the curvature of the sides and the width of the boxare so interrelated that the concentration of the heavier solids causediirst by the liquid going round a curve and second by the decrease inthe velocity of the stream occurs at the same time and place, thuscausing a maximum concentration of the heavier solids in a minimumrestricted area. The operation with this arrangement is showndiagrammatically in Fig. 3 where it will be seen, for instance, that theow is such that substantially all of the solid particles carried by theliquid are concentrated in the concave curve above A for instance andfrom there the particles spread, the heavier particles going to thelower portion of the dotted outline. The carried particles are thenagain collectedk and forced against the concave curve below B, forinstance, from which they pass and spread so that the heavier particlesare at the upper portion of the dotted area as they pass on to becollected again at the concave wall above C and so on through the entirecourse of the channel. In order to take advantage of this effect thereare placed in the bottom of the channel at the proper points to engagethe heavier particles carried by the liquid, curved riilies or bafflesI9. In a channel of the size indicated above these riifles may be flatstrips fastened to the bottom of the channels of about 1/4 of an inchwide and about 35 of an inch thick. The riflles are preferably curved ona radius of about 7 1/2 inches which is about half the radius of thecurves making up the sides of the channels. The arc of the outer edge ofthe rifiles is about 91/2 inches and it is found convenient to arrangethese rililes with their convex surfaces directed upstream and placed sothat they may receive the heavier particles of the solid materialcarried by the liquid in such a way that the particles may tend to beretarded and deposit and roll more slowly forward along the riilies. Tothis end each riffle may be attached to the bottom so that its end abutsagainst the convex wall slightly in advance of the peak, or at about 1%inches to the right of the curve peak A as indicated in Fig. 3. Theforward end of the riffle then will be about 4% inches to the left ofthe radius passing through the peak of the curve B, and it maypreferably be arranged so that its foremost corner is vertically twoinches below the line which would be tangent to the curve B asillustrated in Fig. 3. In this arrangement it may be convenient andefiicient to provide small holes in the bottom of the trough immediatelyadjacent the down stream edge of the riffle extending backward along thearc a little less than half of its length. One satisfactory arrangementconsists of four of these holes,vone placed about a quarter of an inchback from the down stream end of the riiiie and the other three placedat intervals of about 11/4 inches therefrom.

By this arrangement it will be seen that as the liquid carrying solidspasses through the trough there is a tendency for the heavier particlesto arrange themselves more or less along' the lines D, E and F, G etc.As these heavier particles move forward a considerable portion of themimpinges on the baliles and is directed along the edge of the bafflemore or less along the lines D, H and F, K etc. Thus at each baffle aconsiderable portion of the heavier particles are influenced to progressmore slowly along the edge of the riile and fall through the holes 20into the launder 2 l The curved shape of the rilfle and its location inrespect to the restricted concentration area 'causes a maximum ofheavier solids and a miniof vlighter ones to be deflected along theconvex side' of the riiile over the discharge holes l arrangedaround'its down stream-portion. f

`I` claim as my invention@ t 1. rA concentrator comprising a troughhaving y on radii approxirntelypne hank the radii of the Wall curvesand'presenting their 4convex sides to substantially parallel Wallsformed With succeeding reversed curvesV the curves being on radiiapproximately fourf times the` Width of the trough. 'A

2. A concentratorcomprising a trough having a bottom and substantiallyparallel side Walls formed with succeeding reversed curves, curvedbaffles extending from convex portions of the Walls in the path oftheheaviest particles passing through the concentrator, Landperforations in the bottom of the concentrator adjacent `the baflies."

3.- A concentrator comprising a trough having a bottom and substantiallyparallel side walls formed with succeeding reversed four/es, the curvesbeing on radiiapproximately `foury times the Width of the trough, curvedbaffles in the the-stream, and perforations inthe bottom of ltheco'ncen'trator adjacent the down stream endsr of the convexsides of.the bailes. f

` V8.V A concentrator comprising a trough having a bottom' and ysideWalls formed with succeeding reverse vcurves the convexl curves jonopposite Walls having av common tangent, reversely curved bales in thepathof the heaviest particles the baffles being curved onlradiiapproximately one yhalf the radii' of the Wall curvesk andpresentingtheir convex sides to the stream.' and perforations in the bottom -ofthe concentrator adjacent the` down stream ends of theconvex sidesof the9. VA 'concentrator ``comprising a trough having.

Walls having 'a' commonv tangent, reversely curved baflles in vthe'pathof the heaviest particles and presenting their convex sides tothe pathofthe heaviest particles passing through the concentrator the bafflesbeing curved on radii approximately one half lthe radii of the Wallcurves andpresenting their convex sides to the stream,'and perforationsin the bottom of the concentrator adjacent the bales.

4. A concentrator comprising a trough having a bottom and substantiallyparallel sidewalls formed with ,succeedingr reversed kcurves the curvesbeing on radii approximately kfour times the Width of the trough. curvedbaffles 'inthe path of the rheaviest particles passing rthrough theconcentrator and presenting their convex sides to the stream, andperforations in the bottom of the concentrator'adjacent the baffles.

5. A concentrator comprising a troughhavingi V a bottom andsubstantially parallel side 'Walls` formed with succeeding reversedcurves,ucurved" baffles in the pathvof the heaviest particles passn ingthrough theconcentrator the baffles being curved on radii approximatelyone half the radii of thevvall curves andfpresenting their convex sidesto the stream, and perforations in'the'botbottom of the concentratoradjacentthe-down o stream ends ofthe convex sides of the baiiles. f

'7.l vA concentrator comprising a trough having a'bottom and side Wallsformed vvvithsucceeding reverseV Acurves eachv on a'radiusapproximatelyfour timesr the `Width of the trough V'with the convex curves onopposite Walls having a common tangent, reversely curved baffles in thepathV of the heaviest particles the bafes being curved cent the baffles.

stream' andperforations in i the bottom' of the concentrator adjacentlthe down stream ends of the convex .sidesof-the-bales.' l

l0. A concentrator'y comprising a1 trough-having a bottom and sidewallsformedvwith succeeding reverse curves the convex curves on opposite'walls having a common'tangent, bales in the Apath of the heaviestparticles, and perforations in the Abottom vof the concentratoradja'- i11,;A concentratorcomprising a trough havingy substantially parallelside Walls formed with succeeding adjacenty Jsubstantially similarreversed curves, a substantially smooth bottom for Y the trough havingjperforations therein, and bailles on the bottom adjacent the downstreamsides` of the perforations.

- 12.,A concentratorcomprising a trough. having a bottomk andsubstantially parallel side Walls jin contact with the bottom; andformed with succeeding reversed curves-the degree of curvature beingsuflicient to defle'cttheow of the heaviest particles toward vthe, nextsucceeding concavezside'of the. opposite Wall, and baies in the paths ofther heaviest particles passing f throughthe concentrator.

13. A concentrator comprising a troughhaving a bottomand .substantiallyparallel sidek Walls inv `contact with vthe bottom and formed Withsucceeding longitudinall reversed curves,the succeeding convexcurves onopposite side Walls having o a substantially common tangent.

L14. concentrator comprising'al trough havt. ing a bottom andsubstantially parallel side Walls in `'contact vwith the bottom andformed with succeeding, substantially smilar,longitudinal remon tangent.Y

versed -curves,-the succeeding convex curves on opposite `side Walls'having a substantially com'- WALLER C. HUDSON.

